Welcome Guest [Log In] [Register]
Welcome to The New Coffee Room. We hope you enjoy your visit.


You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are some features you can't use. If you join our community, you'll be able to access member-only sections, and use many member-only features such as customizing your profile, sending personal messages, and voting in polls. Registration is simple, fast, and completely free.


Join our community!


If you're already a member please log in to your account to access all of our features:

Username:   Password:
Add Reply
Cloaking devices improved; beware the Klingons
Topic Started: Jan 22 2009, 07:51 AM (248 Views)
big al
Member Avatar
Bull-Carp
Quote:
 
A disappearing act Version 2.0

As math gets more complex, it can make students disappear. But when you add complex algorithms, you can make almost anything disappear.

That is because a new version of a cloaking device is now closer to reality.

After first demonstrating the feasibility of such a device by constructing a prototype in 2006, a team of Duke University engineers created a new type of cloaking device, which is significantly more sophisticated at cloaking in a broad range of frequencies.

The latest advance came from developing a series of complex algorithms to guide the design and fabrication of metamaterials. You can engineer these materials to have properties not easily found in natural materials, which could result in forming a variety of “cloaking” structures. These structures can guide electromagnetic waves around an object, only to have them emerge on the other side as if they had passed through an empty volume of space.

Once the Duke team created the algorithm, they were able to put the cloaking device together from conception to fabrication in nine days. The previous version took four months for a more basic device. This powerful new algorithm will make it possible to custom-design unique metamaterials with specific cloaking characteristics, the researchers said.

“The difference between the original device and the latest model is like night and day,” said David R. Smith, a member of the Duke team. “The new device can cloak a much wider spectrum of waves—nearly limitless—and will scale far more easily to infrared and visible light. The approach we used should help us expand and improve our abilities to cloak different types of waves.”

Cloaking devices bend electromagnetic waves, such as light, in such a way that it appears as if the cloaked object is not there. In the latest laboratory experiments, a beam of microwaves aimed through the cloaking device at a “bump” on a flat mirror surface bounced off the surface at the same angle as if the bump were not present. Additionally, the device prevented the formation of scattered beams that you would normally expect from such a perturbation.

The underlying cloaking phenomenon is similar to the mirages seen ahead at a distance on a road on a hot day.

“You see what looks like water hovering over the road, but it is in reality a reflection from the sky,” said Smith. “In that example, the mirage you see is cloaking the road below. In effect, we are creating an engineered mirage with this latest cloak design.”

Smith said cloaks should find numerous applications as they perfect the technology. By eliminating the effects of obstructions, cloaking devices could improve wireless communications, or acoustic cloaks could serve as protective shields, preventing the penetration of vibrations, sound or seismic waves.

“The ability of the cloak to hide the bump is compelling, and offers a path towards the realization of forms of cloaking abilities approaching the optical,” said Ruopeng Liu, a lead author of a paper on the subject and a Duke team member. “Though the designs of such metamaterials are extremely complex, especially when traditional approaches are used, we believe that we now have a way to rapidly and efficiently produce such materials.”

With appropriately fine-tuned metamaterials, you could redirect at will electromagnetic radiation at frequencies ranging from visible light to radio for virtually any application, Smith said. This approach could also lead to the development of metamaterials that focus light to provide more powerful lenses.

The newest cloak, which measures 20 inches by 4 inches and less than an inch high, has more than 10,000 individual pieces arranged in parallel rows. Of those pieces, more than 6,000 are unique. Each piece has the same fiberglass material used in circuit boards and etched with copper.

The algorithm determined the shape and placement of each piece. Without the algorithm, properly designing and aligning the pieces would have been extremely difficult, Smith said.


Source: A Disappearing Act - Version 2.0

Man, I sure wish I had one of them there cloaking devices around here sometimes. It would be even better than an "Ignore" function.

Big Al
Location: Western PA

"jesu, der simcha fun der man's farlangen."
-bachophile
Offline Profile Quote Post Goto Top
 
Mikhailoh
Member Avatar
If you want trouble, find yourself a redhead
I wish I had a home one.
Once in his life, every man is entitled to fall madly in love with a gorgeous redhead - Lucille Ball
Offline Profile Quote Post Goto Top
 
Mark
Member Avatar
HOLY CARP!!!
Screw cloaking where is the transporter???
___.___
(_]===*
o 0
When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
Offline Profile Quote Post Goto Top
 
Lucky Lurker
Member Avatar
Junior Carp
Well, I can't see this happening.
Sock puppet permit rejected.
Still a man hears what he wants to hear and disregards the rest.
Offline Profile Quote Post Goto Top
 
Mark
Member Avatar
HOLY CARP!!!
It's so transparent.
___.___
(_]===*
o 0
When I see an adult on a bicycle, I do not despair for the future of the human race. H.G. Wells
Offline Profile Quote Post Goto Top
 
ivorythumper
Member Avatar
I am so adjective that I verb nouns!
big al
Jan 22 2009, 07:51 AM


Man, I sure wish I had one of them there cloaking devices around here sometimes. It would be even better than an "Ignore" function.

Big Al
Oh come on and admit -- you really just want to hang around the girls locker room.
The dogma lives loudly within me.
Offline Profile Quote Post Goto Top
 
JoeB
Member Avatar
Senior Carp
Mark
 
Screw cloaking where is the transporter???

IBM
 
In 1993 an international group of six scientists, including IBM Fellow Charles H. Bennett, confirmed the intuitions of the majority of science fiction writers by showing that perfect teleportation is indeed possible in principle, but only if the original is destroyed. In subsequent years, other scientists have demonstrated teleportation experimentally in a variety of systems, including single photons, coherent light fields, nuclear spins, and trapped ions. Teleportation promises to be quite useful as an information processing primitive, facilitating long range quantum communication (perhaps unltimately leading to a "quantum internet"), and making it much easier to build a working quantum computer. But science fiction fans will be disappointed to learn that no one expects to be able to teleport people or other macroscopic objects in the foreseeable future, for a variety of engineering reasons, even though it would not violate any fundamental law to do so.

Source
"There are many ingredients in the stew of annoyance." - Bucky Katt
Offline Profile Quote Post Goto Top
 
Frank_W
Member Avatar
Resident Misanthrope
I could really use one of those.
Anatomy Prof: "The human body has about 20 sq. meters of skin."
Me: "Man, that's a lot of lampshades!"
Offline Profile Quote Post Goto Top
 
« Previous Topic · The New Coffee Room · Next Topic »
Add Reply